Search results

Heathkit Icom Kenwood Power Transistors Ten Tec Yaesu spare Hamradio parts.

Chart showing how SWR effects how much power you actually radiate from your antenna.

Article on tubes and their usage in power amplifiers design. Explain failures of tube in RF power amplifiers, a common problem in the SB-220 SB-221, TL-922 and other amplifiers.

The GM4JJJ VHF and EME pages document David's extensive work in Earth-Moon-Earth (EME) communication, specifically on the 144 MHz band, and his involvement in amateur radio astronomy. The resource details his station setup and operational experiences, providing insights into the technical challenges and rewards of bouncing signals off the moon. It offers a glimpse into the specialized equipment and techniques required for successful EME contacts, a niche but highly rewarding aspect of amateur radio. David's content shares practical applications and field results from his EME endeavors, which can be particularly useful for hams contemplating or actively pursuing moonbounce operations. The information, while not a step-by-step guide, implicitly compares the complexities of EME with more conventional VHF/UHF operations, highlighting the significant power and antenna gain necessary to overcome path losses. This resource serves as a testament to the advanced capabilities achievable in amateur radio.

The BP-3 was a valve-based spy radio transceiver, developed during WWII by Tadeusz Heftman of the Polish Military Wireless Unit in Stanmore (UK). It was introduced in 1943 and was intended for use by Agents and Resistance Organisations in Europe. The transmitter produces an output power of 50 Watts in CW

Kenwood Ibérica's online presence details their extensive product line, including the NEXEDGE NXDN and DMR digital radio systems, alongside traditional analog offerings. The site categorizes transceivers by mode, such as HF / Todo Modo (All Mode), and portable/mobile VHF/UHF units, catering to various amateur radio operating preferences. This includes specific accessories like batteries, chargers, microphones, and programming cables, essential for maintaining and customizing radio equipment. The Spanish portal also highlights Kenwood's broader electronics portfolio, extending beyond amateur radio. This encompasses car electronics, featuring navigation and multimedia systems, as well as marine receivers and speakers. The product range covers everything from CD and CD-less car receivers to power amplifiers and DashCam/RearCam solutions, demonstrating the brand's diverse market reach. Beyond communications gear, the site presents home audio systems, including all-in-one receivers and portable party speakers. This breadth of offerings underscores Kenwood's long-standing presence in both the consumer electronics and two-way radio sectors, providing a centralized resource for product information and support.

A simple 50 ohm dummy load to test transmitters. includes a simple RF diode detector to measure the peak voltage, and calculate the power

Protecting amateur radio equipment from transient overvoltages requires robust lightning and surge protection, which is the focus of Electronic Specialty Products. The company provides various devices, including coaxial lightning arrestors for antenna feedlines and surge protectors for AC power lines and data circuits. These devices are engineered to divert high-energy surges, such as those caused by direct or indirect lightning strikes, away from sensitive transceivers, amplifiers, and computer components, thereby preventing catastrophic damage. Key products include the _Coaxial Lightning Protector_ series, designed for various impedance levels and frequency ranges up to 3 GHz, and the _AC Line Surge Protector_ for shack power distribution. Effective deployment of these protection devices can significantly reduce the risk of equipment failure and ensure operational continuity during severe weather. For instance, a properly installed coaxial arrestor can handle peak currents of **20 kA**, while AC line protectors offer clamping voltages typically below 400V. Comparing different models reveals varying levels of insertion loss and return loss, with some coaxial units exhibiting less than 0.1 dB loss at 500 MHz, making them suitable for high-performance HF and VHF/UHF operations. Integrating these components into a comprehensive grounding system is crucial for achieving maximum protection against both common-mode and differential-mode surges.

A PowerPoint presentation by Bruce Draper, AA5B on how to get started in contesting, no matter if you are a big gun or a little pistol

Demonstrates the operational status and reception reports for the SK6RUD/SA6RR QRPP beacons, which transmit on 478.9 kHz, 1995 kHz, 10.131 MHz, and 40.673 MHz. These beacons utilize extremely low power, with the 630-meter beacon operating at approximately 0.1 watt ERP into an L-antenna, showcasing the potential for long-distance contacts under favorable propagation conditions. The site details the specific frequencies and antenna types employed, such as a vertical at 500 kHz and a 1/4 vertical for higher bands. The resource compiles over 10,530 reception reports from amateur radio operators worldwide, logging details such as date, time, band, RST signal report, locator, distance, and receiver setup. Notable long-distance reports include a 500 kHz reception by AA1A-Dave from 5832 km in 2008 and a 10.133 MHz reception by ZL2FT-Jason from 17680 km in 2010, illustrating the global reach of these low-power transmissions. Each log entry provides specific equipment used by the reporting station, including transceivers like the Yaesu FT817, ICOM IC-7300, and various antenna configurations such as coaxial mag loops, inverted Ls, and end-fed wires. The primary objective of the SK6RUD beacons is to challenge conventional notions of power requirements for effective two-way communication, proving that contacts over significant distances are achievable with minimal output. The site also includes a submission form for new reception reports, fostering community engagement and continuous data collection on propagation phenomena across different bands. The detailed logs offer practical insights into real-world propagation characteristics and the efficacy of QRPP operations.

A home made VHF 2.5kw RF power amplifier made with a GS35B Triode and designed by Frank F1CXX built in 2003

Portable electronics, amateur radio, pro audio and digital cameras batteries, chargers and conditioners.

The purpose of this project is to build a smart switch A smart swith is a swith that needs a short press and the power will be turned ON.

VHF RF power amplifiers manufacturerr

QST Article on what you should know about matching networks for class C RF power amplifiers

Schematic diagram of the VLA 200 power amplifier by RM Italy

VHF Power amplifier VLA 200 english manual

Free basic and advanced system design tutorials for every component and aspect of solar power. Plus system sizing calculators, battery bank calculators and wire size calculators

Batteries for all your portable power needs.

4CX1500B RF amplifier schematic, working 1.8 MHz to 29.7 MHz

The article details a specific method for performing maintenance on a crank-up tower, focusing on cable and rotator replacement without a full power pulldown. It outlines the necessary equipment, including a 2-section extension ladder with a horn attachment and a two-piece, 6-foot steel pipe, specifying a 1 1/4-inch diameter. The procedure involves lowering tower sections onto the internal pipe to slacken cables, allowing for their removal and replacement, and also describes how to replace the rotator while the tower remains upright. Key steps involve using the pipe to support tower sections, enabling access to the cables and bearings. The author, N5AR, emphasizes safety by instructing the reader to remain on the ladder at all times, rather than climbing the tower itself. The process is presented as manageable for a single operator, with the author having successfully completed the task on a _UST TX472_ tower. Specific tools mentioned include Allen wrenches and end wrenches for cable ends and bearing bolts. The method provides a practical approach for tower upkeep, minimizing the complexity often associated with such tasks and allowing for maintenance of components like cable pulleys and their bearings.

A system designed to automatically tune small transmitting magnetic loop antennas, particularly beneficial for **contest operations** where rapid frequency changes are common. The core of the system involves a PC-based control application, AutoCap, written in C#, which monitors antenna SWR via an external meter and commands a motor interface to adjust the loop's variable capacitor. The software is compatible with Windows and Linux via the Mono framework, offering a graphical user interface for monitoring system status, SWR, power, and motor commands. Key components include one or more magnetic loop antennas equipped with DC or stepper motors for capacitor adjustment, an SWR meter with data output (such as the Telepost LP-100A or a homebrew serial/USB SWR meter), the AutoCap PC software, and a motor interface. The most effective motor interface utilizes an **Arduino-based controller** with custom firmware, providing precise control over both simple DC motors and stepper motors, and supporting features like motor braking for finer adjustments. The system allows for configurable SWR thresholds, pulse widths, and motor effort settings to optimize tuning speed and resolution. Optional radio integration provides frequency hints, enabling the algorithm to learn the relationship between motor actions and resonant frequency, thereby speeding up initial tuning responses. The software also supports antenna profiles, allowing operators to save and recall specific configurations for different loops, including accumulated frequency hint data.

Anderson Power Products specializes in high-current interconnect solutions, featuring products like the _Industrial Battery Connector_ (IBC) DIN-style connector for advanced battery charging applications. Their product line includes the SBS®XPRO connector, designed with three power contacts and eight signaling contacts, suitable for battery-powered equipment in harsh environments. The new Saf-D-Grid® Max connector supports up to **55A** and 600V, providing high power density in a C19 footprint, and is UL-rated for disconnect up to **40A**. They also offer IP68-rated SBS®X-75A connectors, engineered for waterproof high power and signal transmission. The company provides pre-crimped cable assemblies, simplifying proper contact maintenance between cables and connectors. Anderson Power Products serves diverse sectors including material handling, electric vehicles, telecom, office equipment, and power management, emphasizing reliable and rugged connector designs. Technical documentation and a comprehensive power connector catalog are available for detailed product specifications.

PSELab is a freeware Windows application useful to estimate power spectrum and short-time spectral distribution of signals. The application uses periodogram, least squares Prony, Burg, covariance, MUSIC and some other methods. To estimate short-time spectral distribution, the application uses short Time Fourier transform, pseudo-Wigner-Ville transform, least squares Prony, Burg, covariance, MUSIC and some other methods.

Magnetic Loop Antennas for The Radio Operator with Limited Space, a two part series of articles on how to construct a magnetic loop antenna, including directions on selecting high voltage tuning capacitor

Antenna tuners are crucial for matching the impedance of antennas to the 50 ohm output impedance of transmitters. The _LDG Z-11 Pro_ is an automatic antenna tuner designed to handle up to 125 watts, making it suitable for a wide range of amateur radio applications. Its compact form factor allows it to pair well with transceivers like the _FT-857D_, providing a portable solution for operators who frequently change locations or setups. The tuner covers the 80 through 6 meter bands, offering a broad impedance match capability. Although it struggles with some loads, it performs well with typical ham antennas, even managing to load an 80 meter dipole on 6 meters. One of the standout features of the _Z-11 Pro_ is its 8000 memory slots, which enable it to remember successful matches and quickly retune when revisiting frequencies. This memory function significantly reduces tuning time, often to less than half a second. The unit is well-constructed, with improved pushbuttons and a sturdy metal case that offers good shielding. However, users should be aware of potential RFI issues and the lack of a power switch, which requires disconnecting the power cord to turn off the unit completely. Overall, the _LDG Z-11 Pro_ is a user-friendly and cost-effective tuner, offering advanced features that enhance its utility in various amateur radio setups.

T-Match Network Antenna Tuner for a wide range of complex antenna loads between 1.8 and 30Mhz at moderate power levels by VK6YSF

Relay substitution tutorial, power amplifier tuning and Technical Characteristics

Pioneer supplier in the radio parts field, and electronic components, alternative power products, kits, test equipment and computer components.

SDR-Radio.com is a Windows console for Software Defined Radio (SDR) receivers and transceivers. Designed for the commercial, government, amateur radio and short-wave listener communities, the software provides a powerful interface for all SDR users

Win EA6DDlog is a freeware logging application for Windows, developed by EA6DD Biel. It integrates features from existing software like Swislog, Urelib, Logger, and HamRadio Deluxe, presenting a Multi-Document Interface (MDI) similar to Logger. The program prioritizes simplicity, practicality, and operational speed, allowing functionality even on less powerful PCs. It does not require a formal installation; users can run it directly from a portable drive or any directory. This logging utility supports CAT control through Omnirig by Alex Shovkoplyas, VE3NEA, which is automatically installed if not already present on the system. It also offers QSL printing capabilities and connections to online callbook services such as QRZ and HamQTH for contact information. EA6DDlog includes an automatic update mechanism that checks for new versions upon startup, requiring internet access. For Windows Vista users, disabling User Account Control (UAC) is recommended for proper update functionality. The software is part of a broader development effort aiming for cross-platform compatibility, with future versions planned for Windows Mobile, Linux, and macOS.

ECONCO has been rebuilding vacuum tubes for more than 30 years. Our commitment to quality, and concern for the environment has won us the acclaim of clients worldwide.

Improving measurement accuracy when low-power analyzers are used.

Errante's virtual ground Balun, a state-of-the-art high power HF balun family.

Mitigating RF noise in a mobile operating environment, particularly within a _Jeep TJ_ vehicle, presents unique challenges due to the vehicle's electrical system and chassis characteristics. This resource details practical methods for identifying and suppressing various forms of radio frequency interference (RFI) that can degrade receiver performance for both CB and amateur radio transceivers. It covers common noise sources such as ignition systems, alternators, fuel pumps, and computer modules, explaining how these components generate broadband or specific frequency noise that impacts radio communications. The guide offers actionable solutions, including proper grounding techniques, the strategic use of ferrite beads and toroids on power and data lines, and the installation of bypass capacitors. It discusses the effectiveness of different filtering strategies for DC power lines and antenna feedlines, illustrating how a clean power supply and shielded cabling can significantly reduce conducted and radiated noise. The information presented helps operators achieve a lower noise floor, improving signal-to-noise ratio and enabling clearer reception of weak signals, which is crucial for effective mobile DXing or local ragchewing.

Operating magnetic loop antennas requires careful consideration of RF safety, particularly regarding near-field magnetic field intensity. This resource presents calculations for magnetic field strength (H-field) at various distances from a magnetic loop, emphasizing that the H-field is significantly higher than the E-field in the near-field region due to the inductive nature of the radiating element. It provides specific formulas and examples for determining safe operating distances based on power levels and loop dimensions, crucial for compliance with RF exposure limits. The analysis compares calculated H-field values against FCC and ICNIRP maximum permissible exposure (MPE) limits for controlled and uncontrolled environments. It demonstrates that even at QRP power levels (e.g., 5W), the H-field can exceed MPE limits within a few feet of the antenna, necessitating greater separation distances than often assumed for electric field considerations. The practical application of these calculations helps amateur radio operators configure their stations to ensure personnel safety and regulatory compliance when deploying compact, high-Q magnetic loop antennas.

ON6MU Low Power amplifier

DK7ZB's fan dipole designs address the challenge of operating multiple HF bands with a single feedline, providing practical construction details for **multiband wire antennas**. The resource outlines specific lengths for half-dipoles across various band combinations, including 10-15-20m for classic bands and 12-17-30m for WARC bands. It emphasizes the importance of proper spacing between resonant elements to avoid impedance interaction and high SWR, a common issue when frequencies are too close. The article details the use of **current baluns** built with FT240-43 or FT140-43 cores, specifying turns and cable types for 1KW and 400-Watt power levels. It includes a correction table for adjusting dipole lengths based on frequency shifts, aiding in fine-tuning resonance. The 20+40m dipole is noted for its ability to operate on 15m with an ATU, demonstrating versatility.

Digital radio mondiale DRM products, measuring tools, Magnetic field probes, RF power meters, Broadband loop antennas, DRM devices and services

NU-Tech is a powerful DSP platform to validate and real-time debug complex algorithms, simply relying on a common PC. Thanks to an easy plug-in architecture, the developer can write his own NUTSs (NU-Tech Satellites) in C++ and immediately plug them into the graphical interface design environment.

The WaveNode WN-1 is a precision, full-featured Amateur Radio Station Monitoring System which now includes Audio Announcing for RF power, SWR, and DC monitoring using HF and UHF remote sensors.

A Portable 100 watt radio station setup composed by a 706MKII transceiver, Z-100 antenna tuner and power supply by N1GY

The practice of converting computer server power supplies to make a very high quality high power supply at low cost is attractive. It doesn't normally require any modification to the supply but the hard part is figuring out how to trick them into turning on.

The Ameritron ALS-600 600-Watt HF Power Amplifier review by AD5X

Amateur radio accesories, power supplies, electronic parts, antenna controllers and antennas manufacturer based in Spain

Manufacturer industrial and consumer power supply products including switching power supplies, solar panels, solar charge controllers, inverters.

A handy piece of test equipment useful for HF bands, can absorb a 200W modulated carrier for almost 2 minutes. It is housed in a tin and part filled with dry sand that helps in power dissipation

An SSB radio for the HF bands will be presented. Featuring 12 to 20 Watts of output power (depending on DC supply), full DDS frequency generation, covering 6 major frequency bands (1.8, 3.5, 7, 14, 21 and 28 MHz) within the short wave amateur radio spectrum. The rig also features colored LCD and front panel backlight.

Presents the construction of a 2-meter **Skeleton Slot Yagi** stack, detailing the design process and practical considerations for VHF operation. The author shares insights from building and testing this antenna, emphasizing its performance characteristics for local and extended range contacts. The project outlines the specific dimensions and materials used, providing a clear path for other radio amateurs to replicate or adapt the design for their own stations. The resource covers the unique aspects of the Skeleton Slot radiator, explaining how its geometry contributes to gain and pattern control. It includes discussions on impedance matching and feedline considerations crucial for optimizing power transfer and minimizing SWR. The article draws on real-world testing, offering practical results that validate the theoretical design. This project serves as a valuable reference for those interested in custom VHF antenna solutions.

Low power radio modules - supplying rf modules, rf transceivers, radiometrix transmitters receivers, low power radio modules, scada, frequency hopping, 900 mhz, wireless data transmission, data telemetry, gps modules & receivers and more